Vascular endothelial growth factor induces endothelial fenestrations in vitro

Item Type:	Review
Title:	Vascular endothelial growth factor induces endothelial fenestrations in vitro
Creators Name:	Esser, S. and Wolburg, K. and Wolburg, H. and Breier, G. and Kurzchalia, T. and Risau, W.
Abstract:	Vascular endothelial growth factor (VEGF) is an important regulator of vasculogenesis, angiogenesis, and vascular permeability. In contrast to its transient expression during the formation of new blood vessels, VEGF and its receptors are continuously and highly expressed in some adult tissues, such as the kidney glomerulus and choroid plexus. This suggests that VEGF produced by the epithelial cells of these tissues might be involved in the induction or maintenance of fenestrations in adjacent endothelial cells expressing the VEGF receptors. Here we describe a defined in vitro culture system where fenestrae formation was induced in adrenal cortex capillary endothelial cells by VEGF, but not by fibroblast growth factor. A strong induction of endothelial fenestrations was observed in cocultures of endothelial cells with choroid plexus epithelial cells, or mammary epithelial cells stably transfected with cDNAs for VEGF 120 or 164, but not with untransfected cells. These results demonstrate that, in these cocultures, VEGF is sufficient to induce fenestrations in vitro. Identical results were achieved when the epithelial cells were replaced by an epithelial-derived basal lamina-type extracellular matrix, but not with collagen alone. In this defined system, VEGF-mediated induction of fenestrae was always accompanied by an increase in the number of fused diaphragmed caveolae-like vesicles. Caveolae, but not fenestrae, were labeled with a caveolin-1-specific antibody both in vivo and in vitro. VEGF stimulation led to VEGF receptor tyrosine phosphorylation, but no change in the distribution, phosphorylation, or protein level of caveolin-1 was observed. We conclude that VEGF in the presence of a basal lamina-type extracellular matrix specifically induces fenestrations in endothelial cells. This defined in vitro system will allow further study of the signaling mechanisms involved in fenestrae formation, modification of caveolae, and vascular permeability.
Keywords:	Antibodies, Caveolin 1, Caveolins, Cultured Cells, Choroid Plexus, Coculture Techniques, Cytoplasmic Granules, Endothelial Growth Factors, Vascular Endothelium, Epithelial Cells, Extracellular Matrix, Gene Expression, Growth Factor Receptors, Intracellular Membranes, Lymphokines, Membrane Proteins, Phosphorylation, Receptor Protein-Tyrosine Kinases, Tissue Distribution, Transfection, Vascular Endothelial Growth Factor A, Vascular Endothelial Growth Factors, Vascular Endothelial Growth Factor Receptors, Animals, Cattle, Mice
Source:	Journal of Cell Biology
ISSN:	0021-9525
Publisher:	Rockefeller University Press
Volume:	140
Number:	4
Page Range:	947-959
Date:	23 February 1998
Official Publication:	https://doi.org/10.1083/jcb.140.4.947
PubMed:	View item in PubMed

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